The subject matter disclosed herein relates to a lamp assembly for a thermographic nondestructive evaluation system.
Infrared (IR) transient thermography is a nondestructive testing technique that utilizes temporal measurements of heat transference through an object to provide information concerning the structure and integrity of the object. Because heat flow through an object is substantially unaffected by the micro-structure and the single-crystal orientations of the material of the object, an infrared transient thermography analysis is essentially free of the limitations this creates for ultrasonic measurements. In contrast to most ultrasonic techniques, a transient thermographic analysis approach is not significantly hampered by the size, contour, or shape of the object being tested and, moreover, can be accomplished ten to one hundred times faster than most conventional ultrasonic methods when testing objects of large surface area.
Conventionally, an infrared (IR) video camera is used to record and store successive thermal images (frames) of an object surface after heating. Each video image is composed of a fixed number of pixels. In this context, a pixel is a small picture element in an image array or frame, which corresponds to a rectangular area, called a resolution element, on the surface of the object being imaged. Because the temperature at each resolution element is directly related to the intensity of the corresponding pixel, temperature changes at each resolution element on the object surface may be analyzed in terms of changes in pixel contrast. One known contemporary application of transient thermography is to determine the size and relative location (depth) of flaws within solid non-metal composites. Another application of transient thermography is for determining the thickness of metal objects.
Certain transient thermography systems employ a lamp to heat the target object prior to or during acquisition of the thermal images. For example, a lamp may be disposed within an internal cavity of a hollow object, such as a pipe or conduit. An IR video camera may be positioned outside the hollow object and configured to receive thermal images from the object after being heated by the lamp. Unfortunately, due to the shape and/or size of certain internal cavities, typical lamps may be unable to fit within the target object. Accordingly, such objects may be unsuitable for evaluation by a transient thermography system.